inhibitors of protein synthesis II

Question 1

prototype aminoglycoside

Answer 1

streptomycin

Question 2

route of administration of streptomycin

Answer 2

IV; IM

Question 3

List the aminoglycosides

Answer 3

1. Streptomycin
2. Gentamicin
3. Tobramycin
4. Amikacin
5. Neomycin

Question 4

route of administration of Gentamicin

Answer 4

• IV
• IM
• topical

Question 5

route of administration of Tobramycin

Answer 5

• IV
• IM
• topical

Question 6

route of administration of amikacin

Answer 6

• IV
• IM

Question 7

route of administration of Neomycin

Answer 7

• oral
• topical

Question 8

why is structure of aminoglycosides significant to their function

Answer 8

• aminoglycosides are polar and very large
• need to be actively transported (oxygen requiring process)
• under aerobic conditions, aminoglycoside are bactericidal
• NOT effective against anaerobic species

Question 9

MOA of aminoglycoside

Answer 9

• irreversibly inhibit protein synthesis
• bind to 30S
• bactericidal

Question 10

coverage of aminoglycoside

Answer 10

• aerobic G - enteric bacteria
• suspicion of sepsis or endocarditis

Question 11

DOC for enterococcus species

Answer 11

aminoglycoside + penicillin

Question 12

DOC tularemia (rabbit hunting disease)

Answer 12

Gentamicin

Question 13

DOC pseudomonas aeruginosa

Answer 13

aminoglycoside + antipseud. pencillin

Question 14

aminoglycosides are time or concentration dependent killers

Answer 14

concentration dependent killing

• increasing concentrations kill an increasing population os bacteria and at a more rapid rate

Question 15

aminoglycoside have a significant post-antibiotic effect. What does this mean?

Answer 15

• antibacterial activity persists beyond the time that the abx is measurable
• single, large does has better efficacy than multiple smaller doses (reduces the toxic side effects)

Question 16

aminoglycoside toxicity

Answer 16

• ototoxicity
• nephrotoxicity

Question 17

why is it bad if a bacteria acquires resistance to one aminoglycoside

Answer 17

• cross resistance
  
  • may exhibit cross resistance to the other aminoglycosides

Question 18

are aminoglycosides mostly used alone to treat infections?

Answer 18

No, they are mostly used in combination with other abx

Question 19

coverage of Chloramphenicol (chloromycetin)

Answer 19

broad spectrum antibiotic

• not first choice-reserved to life threatening infections

Question 20

toxicity of Chloramphenicol (chloromycetin)

Answer 20

• dose-dependent
  
  • fatal aplastic anemia
  • bone marrow suppression
  • “Gray baby” syndrome

Question 21

MOA of Chloramphenicol (chloromycetin)

Answer 21

• reversibly binds the 50S subunit
• protein synthesis is inhibited
• bacteriostatic

Question 22

adverse effect of MOA of Chloramphenicol (chloromycetin)

Answer 22

can inhibit mitochondrial protein synthesis in mammalian cells

Question 23

route of administration of Chloramphenicol (chloromycetin)

Answer 23

Parenteral

Question 24

distribution of Chloramphenicol (chloromycetin) in the body

Answer 24

• distributed widely in the body including eyes and CNS
  
  • ​BEST CNS penetration

Question 25

metabolism of Chloramphenicol (chloromycetin)

Answer 25

metabolized in the liver; conjugated with glucuronic acid \*has to be conjugated to be eliminated

Question 26

"gray baby" syndrome is associated with Abx

Answer 26

Chloramphenicol (chloromycetin) * inadequate activity of glucuronyl transferase in the newborn liver * inability to conjugate the Abx

Question 27

how do bacteria become resistant to Chloramphenicol (chloromycetin)

Answer 27

produce **acetyl transferase** which acetylates and inactivates Chloramphenicol

Question 28

What are the three Tetracyclines

Answer 28

1. Tetracycline 2. Doxycycline 3. Minocycline

Question 29

what is the prototype tetracycline

Answer 29

tetracycline (Sumycin)

Question 30

route of administration of tetracycline (sumycin)

Answer 30

* oral * topical

Question 31

route of administration of Doxycycline

Answer 31

oral

Question 32

route of administration of minocycline

Answer 32

oral

Question 33

MOA of tetracyclines

Answer 33

* inhibition of bacterial protein synthesis * bacteriostatic * bind reversibly to **30S** ribosomes

Question 34

coverage of tetracyclines

Answer 34

broad spectrum

Question 35

DOC Cholera

Answer 35

Doxycycline

Question 36

DOC Mycoplasma pneumonia

Answer 36

tetracyclines + erythromycin

Question 37

DOC infections with chlamydia

Answer 37

tetracyclines + azithro/erythro

Question 38

DOC Rickettsial infections

Answer 38

tetracyclines

Question 39

Early, localized Borrelia Burgdorferi infection (lyme disease)

Answer 39

Doxycycline

Question 40

DOC Vibrio species

Answer 40

tetracyclines

Question 41

tetracycline chelate with what metals

Answer 41

* calcium * iron (Fe2+) * aluminum (Al3+)

Question 42

deposition of tetracycline

Answer 42

deposit in bone and teeth (chelate Ca2+)

Question 43

route of administration of tetracycline

Answer 43

oral is adequate but incomplete

Question 44

adverse reactions of tetracyclines

Answer 44

* normal flora changes * bone (inhibit bone elongation) and Teeth (dental discoloration) * photosensitivity

Question 45

who should not be given tetracyclines

Answer 45

* pregnant women * can cross placenta and is excreted in breast milk * children below the age of 8 years old

Question 46

What is the only Glycylcycline

Answer 46

Tigecycline (tigacil)

Question 47

MOA of Tigecycline

Answer 47

* binds to 30S * bacteriostatic

Question 48

coverage of Tigecycline

Answer 48

* similar to that of tetracycline, doxycycline, minocycline but shows activity against tetracycline-resistant organisms

Question 49

what specific organisms does Tigecycline cover

Answer 49

* MRSA * MRSE (staph epidermidis) * PRSP (PCN-resistant strep pneumoniae) * VRE (vancomycin-resistant enterococci)

Question 50

what are the longer acting tetracyclines

Answer 50

* Doxycycline and Minocycline * slowly excreted * have longer plasma half-life and require less frequent administration